Don't mark IFUNC resolver as only called directly

Don't mark IFUNC resolver as only called directly

Since IFUNC resolver is called indirectly, don't mark IFUNC resolver as
only called directly.  This patch adds ifunc_resolver to cgraph_node,
sets ifunc_resolver for ifunc attribute and checks ifunc_resolver
instead of looking up ifunc attribute.

gcc/

	PR target/85345
	* cgraph.h (cgraph_node::create): Set ifunc_resolver for ifunc
	attribute.
	(cgraph_node::create_alias): Likewise.
	(cgraph_node::get_availability): Check ifunc_resolver instead
	of looking up ifunc attribute.
	* cgraphunit.c (maybe_diag_incompatible_alias): Likewise.
	* varasm.c (do_assemble_alias): Likewise.
	(assemble_alias): Likewise.
	(default_binds_local_p_3): Likewise.
	* cgraph.h (cgraph_node): Add ifunc_resolver.
	(cgraph_node::only_called_directly_or_aliased_p): Return false
	for IFUNC resolver.
	* lto-cgraph.c (input_node): Set ifunc_resolver for ifunc
	attribute.
	* symtab.c (symtab_node::verify_base): Verify that ifunc_resolver
	is equivalent to lookup_attribute ("ifunc", DECL_ATTRIBUTES (decl)).
	(symtab_node::binds_to_current_def_p): Check ifunc_resolver
	instead of looking up ifunc attribute.

gcc/testsuite/

	PR target/85345
	* gcc.target/i386/pr85345.c: New test.

From-SVN: r260547